Messages in this thread | | | Date | Wed, 22 Nov 2006 18:29:14 +0000 | From | Alan <> | Subject | Re: mapping of pages out of upper 128MB into kernel address space |
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On 22 Nov 2006 18:05 GMT <pledr@t-online.de> wrote:
> Hi, > in a kernel module I have to translate user addresses into kernel addresses. The user uses shared memory allocated with shm_open / ftruncate. This shared memory is allocated somewhere in the upmost 128MB of physical memory that is NOT permanently mapped into the kernel ( found in swapper_pg_dir ). How can I "smp_save" map this memory into the kernel address space ?
See how copy_highpage and friends are used by copy_to/from_user. The kmaps are a limited resource so you can only really use them to briefly map objects in this way.
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